Rayleigh-Taylor Instability of a Thin Elastic Solid Impulsively Loaded by a Shock Wave

Growth of instability in a thin elastic solid impulsively driven by a gasdynamic shock tube is studied experimentally. Elastomers of different shear moduli, thicknesses, and initial perturbation wavelengths are examined---the initial perturbations are sinusoidal. The samples are lightly supported in the shock tube test section to avoid the influence of boundary effects. The gas shock reflects off the sample causing it to accelerate due to the reflected shock pressure. The dynamics of the sample is recorded using high-speed videography and photonic Doppler velocimetry (PDV). Two PDV configurations are used: a first configuration tracks the velocity of individual perturbation peaks and troughs, a second configuration uses expanded laser illumination to map the entire surface of the sample. The experimental results are compared against analytical Rayleigh-Taylor stability boundaries found in the literature.